The objective is to undertake an extensive search of genera of the Simaroubaceae and the Meliaceae from the French possessions - Guyana and New-Caledonia - for new Quassinoids and Limonoids, respectively. These compounds are important for their antineoplastic activity. Over the last few years some idea of the structure-activity relationship is being established and therefore the semisynthesis - conversion of inactive to active quassinoids - is also included in the project. My unit at the Institute (at Gif-sur-Yvette) is a leading authority in the chemistry of these structure-types, suffice to give as examples, our structure elucidations of Glucarubinone, Similacalactone D and the different C-l5 esters of Bruceolide (Bruceins A, B, C). The Institute is more than adequately equipped to carry out this study with the availability of a wide range of instrumentation, a pilot plant laboratory, but in particular because of my large collection of standard samples of quassinoids which is invaluable to hasten the identification procedures. The Bioassays for antineoplastic activity have been (supplier not equal to 933F) and will continue to be done by Dr. M. Suffness, NIH and Prof. G.R. Pettit, Cancer Research Institute, Tempe; the antiviral activity is being tested by Dr. M. Gero (I.C.S.N., Gif-sur-Yvette).